Joint plate mounting mechanism

ABSTRACT

A joint plate mounting mechanism includes a backing strip with a first arm, a second arm and a middle portion disposed between the first arm and the second arm.

RELATED APPLICATION

This application claims the benefit of U.S. Provision Patent Application 63/182,128, Filed Apr. 30, 2021, which is expressly incorporated herein.

BACKGROUND State of the Art

In order to train people properly in the use of firearms, it is important that each firearm user receive sufficient experience in live-fire exercises with the weapons which they will be using. Because many bullets contain lead or other materials which can be hazardous to people's health or the environment, it is important to safely contain the projectiles. This is often done in a bullet trap made of hardened steel.

Because bullets and other projectiles are traveling at a high rate of speed, it is important that the bullet trap be made so as to limit the possibility of bullets escaping from the trap. Failure to do so can cause damage to the building housing the trap and potential injury to those in the vicinity.

For decades bullet traps have been formed of plates of hardened steel. In some embodiments, the plates of steel are welded together. While welded pieces form a secure containment structure, the areas at which the plates are welded together are weakened by the welding process. Additionally, if a plate gets damaged, the plate must be cut out and a new piece welded in its place.

For these reasons a system was developed to hold the plates together by applying clamps to sandwich the plates together between a facing strip and a backing strip as discussed in U.S. Pat. No. 5,822,936 ('936 patent). FIG. 1 shows the implementation of the clamping system, generally indicated at 4, when used with a first plate 8 and a second plate 12. The first plate 8 is shown as being disposed generally horizontally, while the second plate 12 is disposed generally vertically. A facing strip 16 is formed having two arms 20 a and 20 b which are generally perpendicular to each other. The arms 20 a and 20 b have holes to receive bolts 24 extending therethrough. The bolts include a bolt head 28 disposed on one side of the arm 20 a or 20 b, and a nut 32 disposed on the other side. A backing washer 36 may be disposed along the shaft of the bolt 24 so that it is held in place by the head 24 or nut 32 (depending on how the bolt is inserted through the arm 20 a or 20 b). The plates 8 and 12 are held in place by positioning edges 8 a and 12 a of the plates adjacent their respective bolts 24 and tightening the bolt so that the backing washer 36 sandwiches the plate 8 or 12 between the backing washer and the arm 20 a or 20 b of the facing strip 16. A shim 40 is typically disposed on the opposite side of the bolt 24 from the plate 8 or 12 so that the backing washer 36 and the facing strip 16 apply compressive force in an equal manner.

Also shown in FIG. 1 is an angle plate 44 which is designed to protect the bolts 24 from getting damaged by the projectiles being fired at the trap. The angle plate is typically welded to a bolt 48 or bolt shaft. A hole is formed in the face plate 16 so that the bolt 48 can extend through the hole and be held in place by a nut 50.

FIG. 2 shows a side view of the clamping system 4 of the prior art with the plates 8 and 12 being held to the facing strip 16 by the bolts and backing washers 36. Tightening the nuts 32 clamps the plates 8 and 12 between the backing washers 36 and the facing plate 16, and the shims 40 help ensure that the force is more evenly applied. In FIG. 2, the bolts 48 and nuts 50 have been omitted to show the holes 52 in the facing strip 16 used to hold the angle plate in place.

One challenge with bullet traps is that occasionally three plates have to come together. This typically happens in the mouth of the bullet trap. The mouth flares outwardly near to the end to direct as much area as possible into the bullet trap—thereby reducing the risk of a shooter missing the trap all together. FIG. 3 shows a cross-sectional view of how the plates 8, 8′ and 12 are brought together. Plate 12 is held to the facing strip 16 by a bolt 24 with a head 28 and a nut 32 in a manner similar to that discussed above. Plate 8, however, has a second horizontal plate 8′ disposed on top thereof. The second horizontal plate 8′ may be disposed immediately adjacent the bolt 24 so that the backing washer 36 rests on top of the second horizontal plate. Two shims 40 are used on the opposing side of the bolt 24 so that when the nut 32 is tightened the backing washer 36 is brought down more evenly, thereby clamping the plate 8 and the plate 8′ between the facing strip and the backing washer.

FIG. 4 shows a cross-sectional view of a joint attachment from the '936 patent. Rather than using backing washers and shims to apply a compressive force on the plates, the embodiment shown in FIG. 4 shows a clamping system 4 in which a horizontal plate 8 is attached to a vertical plate 12 by a facing strip 16 and a backing strip 70, which are drawn together by countersunk bolts 24. By tightening the nuts 32 on the countersunk bolts 24, the facing strip 16 and the backing strip 70 are forced together, thereby applying compressive force on the plates 8 and 12 and holding the plates together. One problem with the facing and backing strips 16 and 70 is that they are generally formed from mild steel because hardened steel may crack when it is bent anywhere near 90 degrees. While the mild steel is easier to bend, it is also more likely to be penetrated by a projectile, such as a bullet. Thus, this leaves a joint which is prone to being damaged by projectiles.

While these methods of holding joints together in a bullet trap or a bullet stop have been used extensively for the last twenty years, they are not without their problems. When a bullet strikes a plate 8 or 12, the bullet is redirected into the containment system of the bullet trap. The steel plates 8 or 12, however, are also deflected by the impact. Repeated impacts can cause the plates to bow or sag. Additionally, the repeated vibrations can loosen the backing washers, and it is not uncommon for them to become sufficiently loose that the shim moves or falls out altogether. This lessens the gripping ability of the backing washer and increases the risk that a gap will open between the plate and the facing strip, thereby allowing bullet fragments or lead dust to escape from the trap.

Thus, there is needed an improved joint plate mounting mechanism which improves the engagement of the plates so as to hold them together more securely.

SUMMARY OF THE INVENTION

The following summary of the present invention is not intended to describe each illustrated embodiment or every possible implementation of the invention, but rather to give illustrative examples of application of principles of the invention.

In accordance with one aspect of the present disclosure, a backing strip is provided for clamping a first plate and a second plate together. The backing strip may have a first arm, and second arm, and a beveled middle section disposed between the arms.

In accordance with one aspect of the invention, the backing strip may include a plurality of slots through which bolts may extend. In some embodiments, slots formed in the arms may extend generally perpendicular to the length of the backing strip. In some embodiments, slots in the middle section may extend generally parallel to the length of the backing strip.

In accordance with another aspect of the present disclosure, a backing band may be provided with a slot in the first arm and a slot in the second arm and no slot in the middle portion.

In accordance with another aspect of the invention, the backing strip may have beveled or tapered ends.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present disclosure are shown and described in reference to the numbered drawings wherein:

FIG. 1 illustrates a cross-sectional view of a clamping system of a joint mounting mechanism of the prior art;

FIG. 2 illustrates a side view of the clamping system shown in FIG. 1;

FIG. 3 shows the joint mounting mechanism of the prior art wherein the clamping system secures three plates together;

FIG. 4 shows an alternate clamping system for a joint mounting mechanism in accordance with the principles of the prior art.

FIG. 5 shows a cross-sectional view of the joint mounting mechanism of an embodiment of the present disclosure;

FIG. 6 shows a perspective view of a backing strip used in accordance with the present disclosure;

FIG. 7 shows a top view of a backing band for use at the intersection of three plates;

FIG. 8 shows a fragmented perspective view of a backing band disposed on a plurality of plates;

FIG. 9 shows a fragmented perspective view of a bullet trap having an inlet portion which is attached in accordance with the principles of the present disclosure;

FIG. 10 shows the inlet portion of a bullet trap having the vertical plates removed; and

FIG. 11 shows a close-up of the portion of FIG. 10 disposed in the dashed circle.

It will be appreciated that the drawings are illustrative and not limiting of the scope of the invention which is defined by the appended claims. The embodiments shown accomplish various aspects and objects of the invention. It will be appreciated that it is not possible to clearly show each element and aspect of the present disclosure in a single figure, and as such, multiple figures are presented to separately illustrate the various details of different aspects of the invention in greater clarity. Similarly, not all configurations or embodiments described herein or covered by the appended claims will include all of the aspects of the present disclosure as discussed above.

DETAILED DESCRIPTION

Various aspects of the invention and accompanying drawings will now be discussed in reference to the numerals provided therein so as to enable one skilled in the art to practice the present invention. The skilled artisan will understand, however, that the methods described below can be practiced without employing these specific details, or that they can be used for purposes other than those described herein. Indeed, they can be modified and can be used in conjunction with products and techniques known to those of skill in the art in light of the present disclosure. The drawings and the descriptions thereof are intended to be exemplary of various aspects of the invention and are not intended to narrow the scope of the appended claims. Furthermore, it will be appreciated that the drawings may show aspects of the invention in isolation and the elements in one figure may be used in conjunction with elements shown in other figures.

Reference in the specification to “one embodiment,” “one configuration,” “an embodiment,” or “a configuration” means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment, etc. The appearances of the phrase “in one embodiment” in various places may not necessarily limit the inclusion of a particular element of the invention to a single embodiment, rather the element may be included in other, or all embodiments discussed herein.

Furthermore, the described features, structures, or characteristics of embodiments of the present disclosure may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details may be provided, such as examples of products or manufacturing techniques that may be used, to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that embodiments discussed in the disclosure may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations may not be shown or described in detail to avoid obscuring aspects of the invention.

Before the present invention is disclosed and described in detail, it should be understood that the present invention is not limited to any particular structures, process steps, or materials discussed or disclosed herein, but is extended to include equivalents thereof as would be recognized by those of ordinary skill in the relevant art. More specifically, the invention is defined by the terms set forth in the claims. It should also be understood that terminology contained herein is used for the purpose of describing particular aspects of the invention only and is not intended to limit the invention to the aspects or embodiments shown unless expressly indicated as such. Likewise, the discussion of any particular aspect of the invention is not to be understood as a requirement that such aspect is required to be present apart from an express inclusion of that aspect in the claims.

It should also be noted that, as used in this specification and the appended claims, singular forms such as “a,” “an,” and “the” may include the plural unless the context clearly dictates otherwise. Thus, for example, reference to “a bracket” may include an embodiment having one or more of such brackets, and reference to “the target plate” may include reference to one or more of such target plates.

As used herein, the term “substantially” refers to the complete or nearly complete extent or degree of an action, characteristic, property, state, structure, item, or result to function as indicated. For example, an object that is “substantially” enclosed would mean that the object is either completely enclosed or nearly completely enclosed. The exact allowable degree of deviation from absolute completeness may in some cases depend on the specific context, such that enclosing nearly all of the length of a lumen would be substantially enclosed, even if the distal end of the structure enclosing the lumen had a slit or channel formed along a portion thereof. The use of “substantially” is equally applicable when used in a negative connotation to refer to the complete or near complete lack of an action, characteristic, property, state, structure, item, or result. For example, structure which is “substantially free of” a bottom would either completely lack a bottom or so nearly completely lack a bottom that the effect would be effectively the same as if it completely lacked a bottom.

As used herein, the term “generally” refers to something that has characteristics of a quality without necessarily being exactly that quality. For example, a structure said to be generally vertical would be at least as vertical as horizontal, i.e., would extend 45 degrees or greater from horizontal. Likewise, something said to be generally circular may be rounded like an oval but need not have a consistent diameter in every direction.

As used herein, the term “about” is used to provide flexibility to a numerical range endpoint by providing that a given value may be “a little above” or “a little below” the endpoint while still accomplishing the function associated with the range.

As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member.

Concentrations, amounts, proportions and other numerical data may be expressed or presented herein in a range format. It is to be understood that such a range format is used merely for convenience and brevity and thus should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. As an illustration, a numerical range of “about 1 to about 5” should be interpreted to include not only the explicitly recited values of about 1 to about 5, but also include individual values and sub-ranges within the indicated range. Thus, included in this numerical range are individual values such as 2, 3, and 4 and sub-ranges such as from 1-3, from 2-4, and from 3-5, etc., as well as 1, 2, 3, 4, and 5, individually. This same principle applies to ranges reciting only one numerical value as a minimum or a maximum. Furthermore, such an interpretation should apply regardless of the breadth of the range, or the characteristics being described.

Turning now to FIG. 5, there is shown a cross-sectional view of a joint mounting mechanism in the form a clamp system 104. The clamp system 104 is similar to that discussed with respect to FIGS. 1-3 above in that it holds a first plate 8 to a second plate 12 and uses a facing strip 16 with a first arm 20 a and a second arm 20 b to clamp against the plates. The embodiment shown in FIG. 5 differs from those discussed above in that it lacks backing washers and shims. Rather, a beveled backing strip 136 is used to engage the first plate 8 and the second plate 12 so as to clamp the first plate 8 between the first arm 20 a of the facing strip 16 and the backing strip 136. The backing strip 136 has a first portion or arm 140 which extends over a lateral edge of the first plate 8 and may have one or more holes 144 (FIG. 6) formed in the first arm 140 of the backing plate. While the holes 144 may be round, preferably the holes 144 are formed as an elongate slot extending generally perpendicular to the length of the backing strip. The elongate slots 144 are desirable above holes because they allow for the backing strip 136 to accommodate different plate thicknesses. For example, depending on the use of the trap, the plates may be ¼, ⅜ths or ½ inch thick. Different plate thicknesses cause the backing plate to be spaced differently from the facing strip 16 and changes the point at which the bolts 24 engage the backing strip. This allows a common backing strip to be used with multiple plate thicknesses.

The first portion or arm 140 extends from a middle portion 148 of the backing strip 136 and is disposed between 40 and 50 degrees, and most preferably disposed at approximately 45 degrees, relative to the middle portion so that the backing strip 136 has a pair of bends extending along its length, with the middle portion 148 being disposed between the bends. The middle portion 148 of the backing strip 136 also includes one or more holes 152 (FIG. 6). The holes 152 are preferably formed as elongate slots which extend generally parallel to the length of the backing strip.

Also extending from the middle portion 148 on a side generally opposite the first portion or arm 140 is a second portion or arm 156. The second arm 156 extends from the middle portion 148 at an angle of between 40 and 50 degrees, and most preferably approximately 45 degrees, so that the first arm 140 and the second arm have lengths which extend generally parallel and widths that extend generally perpendicular to one another. The second arm 156 includes one or more holes 160 (FIG. 6). As with the holes 144 in the first arm, the holes in the second arm are preferably formed as elongate slots which extend generally perpendicular to the length of the back in strip 136 to allow the use of plates of different thicknesses.

The facing strip 16 and the backing strip 136 may be held in a clamping relationship against the first plate 8 and the second plate 12 by the bolts 28 extending through holes 144 and 160 on the backing strip and corresponding holes on the facing strip. The tighter the nuts 32 are turned, the more clamping force is applied by the bolts drawing the facing strip 16 and the backing strip 136 toward each other. It has been found that this configuration improves clamping on the plates 8 and 12, thereby reducing the risk of the plates coming loose. In a presently preferred configuration, the back side of the facing strip 16 makes contact with the backing strip 136.

An angle plate 44 may be held in place by extending the bolt 48 through the facing strip and through hole 152 (FIG. 6) in the middle portion 148 and tightening the nut 50. It has been found that the use of the beveled backing strip 136 provides a significant improvement in holding the plates together so as to prevent fragments passing out of the joint and the joint remaining solid through prolonged use.

Turning now to FIG. 6, there is shown a perspective view of the backing strip 136 used in accordance with the present disclosure. The backing strip 136 may include the first arm 140, the middle portion 148 and the second arm 156 in a beveled configuration such that the first arm and the second arm are disposed approximately 90 degrees from one another measured by their width and extending generally parallel as to their length. The holes 144, formed as elongate slots, may be disposed generally perpendicular to the length of the backing strip 136 and may be positioned so that one end is immediately adjacent the transition from the first arm 136 to the middle portion 148 and spaced from the opposing edge 140 a of the first arm 140. Likewise, the holes 160, which may be formed as slots, in the second arm 156 may be disposed immediately adjacent to the transition between the middle portion 148 and the second arm 156 and spaced away from the lateral edge 156 a of the second arm. The holes 160 may also be disposed so that the slots have a length that extends generally perpendicular to the length of the backing strip 136.

The one or both ends of the backing strip 136 may also be beveled along either or both of the lateral edges 140 a and 156 a of the first arm 140 and the second arm 156. As shown in FIG. 6, the bevels 164 extending to the ends of the first arm are disposed at an angle of between 10 and 20 degrees and extend for a length of 2 to 5 inches. Similarly, the bevels extending to the ends of the second arm are disposed at similar angles and lengths.

The holes 152 along the middle portion 148 are shown as being elongate slots which extend generally parallel to the length of the backing strip 136. The holes 152 may be disposed in the center of the middle portion 148, and may be spaced apart a greater distance than the holes 144 and 160 on the first arm 140 and the second arm 156, respectively, as the holes 152 are used to hold the angle plate in place, rather than holding the plates together.

FIG. 7 shows a top view of a backing band for use at the intersection of three or more plates. The backing band 170 includes a middle portion 174, a first arm 178 and a second arm 182. Each of the first arm 178 and the second arm 182 includes a hole 186 which may be in the form of an elongate slot. The slot is generally longer than the slots in the backing strip so as to enable the backing band 170 to adjust for situations in which three or more plates are coming together.

FIG. 8 shows a fragmented perspective view of a backing band 170 being used to help secure multiple plates coming together. When the intake for a bullet trap tapers as it moves toward the containment chamber, it can be a challenge to secure plates coming in at different angles. In FIG. 8 there is a first plate 8 which is disposed generally horizontally and a second plate 12 which is disposed generally vertically. A third plate 8 a is also disposed generally horizontally and may overlap the first plate. A fourth plate 12 a may overlap the second plate 12 and also be disposed generally vertically, first plate 8 and the second plate 12 may be held together by a backing strip 136, only the end of which is shown in FIG. 8. The backing strip 136 has a middle portion 148 which includes a hole 152, preferably a slot, for receiving the bolt 48 associated with the angle plate.

The third plate 8 a and the fourth plate 12 a are held together by a second backing strip 136 a, only one end of which is shown. The bolts 24 and nuts 32 are disposed in the holes 144 and 160 which are preferably formed as elongate slots. Tightening the nuts 32 clamps the backing strip 136 a to the third plate 8 a and the fourth plate in conjunction with a facing strip (not shown).

While the first and second plates 8 and 12 are securely fastened, and the third and fourth plates 8 a and 12 a are securely fastened, the backing band 170 is used to clamp the third plate 8 a to the first plate 8 to provide additional support at the joint. Tightening the nuts 190 (which extend through a facing strip on the opposing side) clamps the backing band 170 down against the third plate 8 a and the second plate 12 to thereby hold the first, second and third plates together.

Turning now to FIG. 9, where is shown a fragmented perspective view of a bullet trap, generally indicated at 200. The bullet trap 200 includes a containment chamber 204 and an inlet funnel 208. The inlet funnel 208 is formed by a plurality of plates 8, 8 a, 8 b, 12, 12 a and 12 b. The horizontal plates 8, 8 a and 8 b respectively overlap as the inlet funnel moves toward an inlet 212 to the containment chamber. Likewise, the vertical plates 12, 12 a and 12 b, respectively overlap as they move toward the inlet 212. The horizontal plates 8, 8 a and 8 b and the vertical plates 12, 12 a and 12 b are held together by the backing strips 136 and facing strips (which are disposed inside the inlet funnel 208. The overlapping portion of the plates are covered by backing bands 170 to help support the overlapping portion. The backing strips 136 and the backing bands 170 provide a more secure engagement between the plates 8, 8 a, 8 b, 12, 12 a and 12 b and reduce the risk that the plates will come lose and allow bullet fragments or lead dust to escape.

FIG. 10 shows the inlet portion of a bullet trap with the vertical plates removed. The inlet portion has an open end 220 to the right into which bullets or other projectiles may be fired, and a narrow end 224 which forms the inlet 212 which leads into containment chamber shown in FIG. 9. The plates 8, 8 a and 8 b overlap and are held in place by the backing strips 136 and the backing bands 170.

FIG. 11 shows a close-up of the overlapping of plates 8 and 8 b and the associated backing strips 136 and backing band 170. Such structures provide an improved support for the plates to reduce the risk of bullet fragments and/or lead dust escaping the inlet portion between the plate. The system is also modular, thereby allowing a damaged plate to be removed by simply loosening the appropriate bolts and replacing the damaged plate with a new one.

It will be appreciated that numerous variations and combinations of aspect of the present disclosure may be used. For example a bullet trap may have a joint plate mounting mechanism which includes a first plate disposed generally horizontally, a second plate disposed generally vertically, a facing strip having a first arm and a second arm, the first arm engaging the first plate and the second arm engaging the second plate, and a beveled backing strip having a first arm and a second arm, the first arm engaging the first plate and the second arm engaging the second plate.

The bullet trap may include a beveled backing strip which has a middle portion disposed between the first arm and the second arm, and the first arm of the beveled backing strip and the middle portion of the beveled backing strip may be disposed at an angle of between 40 and 50 degrees with respect to one another and more preferably at 45 degrees from one another. The middle portion of the beveled backing strip and the second arm of the beveled backing strip may be disposed at an angle of between 40 and 50 degrees from one another, and preferably at 45 degrees.

The beveled backing strip may have a length the first arm of the beveled backing strip may have a plurality of slots extending through said first arm, the slots extending lengthwise generally perpendicular to the length of the beveled backing strip. The middle portion of the beveled backing strip may include a plurality of elongate slots extending therethrough, and the elongate slots in the middle portion of the beveled backing strip may extend generally parallel with the length of the beveled backing strip.

The first arm of the beveled backing strip may have an outer edge and the second arm of the beveled backing strip may have an outer edge. At least one of the first arm of the beveled backing strip and the second arm of the beveled backing strip may have a bevel along the outer edge of the arm, such that the first arm of the beveled backing strip or the second arm of the beveled backing strip has a width that reduces as it approaches an end of the beveled backing strip. The outer edge of the first arm of the beveled backing strip may be beveled as it extends to both ends of the beveled backing strip, and the outside edges of the first arm of the beveled backing strip and the second arm of the beveled backing strip may both bevel as they approach a common end of the beveled backing strip.

The bullet trap may include a backing band disposed adjacent the beveled backing strip and may include a third plate being disposed horizontally on the first plate, with the backing band engaging the second plate and the third plate. The backing band may include a first arm, a middle portion and a second arm and there may be elongate slots which extend through the first arm and the second arm and wherein the middle portion lacks a hole or slot extending therethrough. The first arm and the second arm of the backing strip may have slots disposed therein and the slots on the backing band may are larger than the slots on first arm and the second arm of the beveled backing strip.

A backing strip for holding together plates in a bullet trap may include a first arm, a second arm and a middle portion, the first arm and the second arm being oriented 90 degrees from one another, and a middle portion disposed between the first arm and the second arm, the middle portion being disposed at an angle of 40 to 50 degrees from the first arm and an angle or 40 to 50 degrees from the second arm relative to a width of the backing strip. The first and second arms may each be at 45 degrees from the middle portion. The first may have a plurality of slots formed therein and the second arm may have a plurality of slots formed therein and the middle portion may have a plurality of slots formed therein.

The backing strip may have a length and the slots in the middle portion may run generally parallel to the length of the backing strip and the slots in the first arm and the slots in the second arm may run generally perpendicular to the length of the backing strip. The slots in the middle portion may be larger than the slots in the first arm and larger than the slots in the second arm.

The first arm may have an outer edge opposite the middle portion and wherein the first arm tapers along the outer edge as the outer edge approaches an end of the backing strip. The second arm may have an outer edge opposite the middle edge and wherein the second arm tapers along the outer edge as the outer edge approaches an end of the backing strip. The backing strip may taper adjacent both ends of the backing strip

A method for forming the inlet of a bullet trap may include selecting a first plate and a second plate and disposing the plates generally perpendicular to one another, disposing a facing strip and a backing strip on opposing sides of the plates and tightening bolts which engage the facing strip and the backing strip to clamp the facing strip and the backing strip against the first plate and the second plate, and were the backing strip has a first arm, a middle portion and a second arm. The first arm may be disposed to engage the first plate, the second arm may be disposed to engage the second plate and the middle portion may be disposed at a 45-degree angle to the first arm and the second arm and does not touch either the first plate or the second plate. The method may include the backing strip having a length and the middle portion having a plurality of slots formed therein, the slots extending generally parallel with length and wherein the method further comprises extending bolts through the middle portion and the facing strip to hold an angle strip in front of the facing strip.

Thus, there is disclosed a joint plate mounting mechanism which facilitates the building of stronger bullet traps. It will be appreciated that modifications may be made in light of the disclosure herein. The appended claims are intended to cover such modifications. 

What is claimed is:
 1. A bullet trap having a joint plate mounting mechanism comprising: a first plate disposed generally horizontally; a second plate disposed generally vertically; a facing strip having a first arm and a second arm, the first arm engaging the first plate and the second arm engaging the second plate; and a beveled backing strip having a first arm and a second arm, the first arm engaging the first plate and the second arm engaging the second plate.
 2. The bullet trap of claim 1, wherein the beveled backing strip has a middle portion disposed between the first arm and the second arm.
 3. The bullet trap of claim 2, wherein the first arm of the beveled backing strip and the middle portion of the beveled backing strip are disposed at an angle of between 40 and 50 degrees with respect to one another and wherein the middle portion of the beveled backing strip and the second arm of the beveled backing strip are disposed at an angle of between 40 and 50 degrees from one another.
 4. The bullet trap of claim 1 wherein the beveled backing strip has a length and wherein the first arm of the beveled backing strip has a plurality of slots extending through said first arm, the slots extending lengthwise generally perpendicular to the length of the beveled backing strip.
 5. The bullet trap of claim 4, wherein the middle portion of the beveled backing strip includes a plurality of elongate slots extending therethrough, and wherein the elongate slots in the middle portion of the beveled backing strip extend generally parallel with the length of the beveled backing strip.
 6. The bullet trap of claim 1 wherein the first arm of the beveled backing strip has an outer edge and wherein the second arm of the beveled backing strip has an outer edge and wherein at least one of the first arm of the beveled backing strip and the second arm of the beveled backing strip has a bevel along the outer edge of the arm, such that the first arm of the beveled backing strip or the second arm of the beveled backing strip has a width that reduces as it approaches an end of the beveled backing strip.
 7. The bullet trap of claim 6 wherein the outer edge of the first arm of the beveled backing strip is beveled as it extends to both ends of the beveled backing strip.
 8. The bullet trap of claim 6 wherein the outside edges of the first arm of the beveled backing strip and the second arm of the beveled backing strip both bevel as they approach a common end of the beveled backing strip.
 9. The bullet trap of claim 1 further comprising a backing band disposed adjacent the beveled backing strip.
 10. The bullet trap of claim 1 further comprising a third plate, the third plate being disposed horizontally on the first plate and wherein the backing band engages the second plate and the third plate.
 11. The bullet trap of claim 10, wherein the backing band includes a first arm, a middle portion and a second arm and wherein there are elongate slots which extend through the first arm and the second arm and wherein the middle portion lacks a hole or slot extending therethrough.
 12. The bullet trap of 11, wherein the first arm and the second arm of the backing strip have slots disposed therein and wherein slots on the backing band are larger than the slots on first arm and the second arm of the beveled backing strip.
 13. A backing strip for holding together plates in a bullet trap, the backing strip comprising a first arm, a second arm and a middle portion, the first arm and the second arm being oriented 90 degrees from one another, and a middle portion disposed between the first arm and the second arm, the middle portion being disposed at an angle of 40 to 50 degrees from the first arm and an angle or 40 to 50 degrees from the second arm relative to a width of the backing strip.
 14. The backing strip of claim 13 wherein the first arm has a plurality of slots formed therein and wherein the second arm has a plurality of slots formed therein and wherein the middle portion has a plurality of slots formed therein.
 15. The backing strip of claim 14, wherein the backing strip has a length and wherein the slots in the middle portion run generally parallel to the length of the backing strip and wherein the slots in the first arm and the slots in the second arm run generally perpendicular to the length of the backing strip.
 16. The backing strip of claim 15, wherein the slots in the middle portion are larger than the slots in the first arm and larger than the slots in the second arm.
 17. The backing strip of claim 13, wherein the first arm has an outer edge opposite the middle portion and wherein the first arm tapers along the outer edge as the outer edge approaches an end of the backing strip.
 18. The backing strip of claim 17, wherein the second arm has an outer edge opposite the middle edge and wherein the second arm tapers along the outer edge as the outer edge approaches an end of the backing strip.
 19. The backing strip of claim 18, wherein the first arm tapers adjacent both ends of the backing strip and wherein the second arm tapers adjacent other ends of the backing strip.
 20. A method for forming the inlet of a bullet trap, the method comprising: selecting a first plate and a second plate and disposing the plates generally perpendicular to one another; disposing a facing strip and a backing strip on opposing sides of the plates and tightening bolts which engage the facing strip and the backing strip to clamp the facing strip and the backing strip against the first plate and the second plate, and were the backing strip has a first arm, a middle portion and a second arm, and wherein the first arm is disposed to engage the first plate, the second arm is disposed to engage the second plate and wherein the middle portion is disposed at a 45-degree angle to the first arm and the second arm and does not touch either the first plate or the second plate.
 21. The method according to claim 20, wherein the backing strip has a length and wherein the middle portion has a plurality of slots formed therein, the slots extending generally parallel with length and wherein the method further comprises extending bolts through the middle portion and the facing strip to hold an angle strip in front of the facing strip. 